Hufflepdf/src/PDF/Text.hs

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{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE FlexibleContexts #-}
module PDF.Text {-(
pageContents
)-} where
import Control.Applicative ((<|>))
import Control.Monad (foldM)
import Control.Monad.Fail (MonadFail)
import Control.Monad.Reader (ReaderT, runReaderT, asks)
import Control.Monad.State (MonadState, evalStateT, get, modify, put)
import Data.Attoparsec.ByteString.Char8 (choice, sepBy)
import Data.ByteString (ByteString)
import Data.ByteString.Char8 (pack, unpack)
import Data.Char (toLower)
import Data.Map ((!), (!?), Map)
import qualified Data.Map as Map (fromList)
import Data.Text (Text)
import PDF.Font (Font, FontSet, emptyFont)
import PDF.Object (
DirectObject(..), StringObject(..)
, array, blank, name, regular, stringObject, toByteString
)
import PDF.Parser (MonadParser(..), (<?>), Parser, evalParser)
data StateOperator =
C_m | W_ | J | J_ | M | D_ | R_i | I_ | G_s -- general graphic state
deriving (Bounded, Enum, Show)
data PathOperator =
M_ | L_ | C_ | V_ | Y_ | H_ | R_e -- path construction
| S | S_ | F_ | F | Fstar | B | Bstar | B_ | B_star | N_ -- path painting
| W | Wstar -- clipping path
deriving (Bounded, Enum, Show)
data ColorOperator =
CS | C_s | SC | SCN | S_c | S_cn | G | G_ | RG | R_g | K | K_
deriving (Bounded, Enum, Show)
data TextOperator =
Td | TD | Tm | Tstar -- text positioning
| TJ | Tj | Quote | DQuote -- text showing
| Tc | Tw | Tz | TL | Tf | Tr | Ts -- text state
deriving (Bounded, Enum, Show)
data Argument = Raw ByteString | Typed DirectObject deriving Show
type Call a = (a, [Argument])
type Operator a = (Bounded a, Enum a, Show a)
code :: Operator a => a -> ByteString
code = pack . expand . show
where
expand "" = ""
expand (c:'_':s) = toLower c : expand s
expand ('s':'t':'a':'r':s) = '*' : expand s
expand ('Q':'u':'o':'t':'e':s) = '\'' : expand s
expand ('D':'Q':'u':'o':'t':'e':s) = '"' : expand s
expand (c:s) = c : expand s
{-
instance Show StateOperator where
show Cm = "cm"
show W_ = "w"
show J = "J"
show J_ = "j"
show M = "M"
show D = "d"
show Ri = "ri"
show I = "i"
show Gs = "gs"
instance Show PathOperator where
show M_ = "m"
show L_ = "l"
show C_ = "c"
show V_ = "v"
show Y_ = "y"
show H_
("m", (M_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False))
, ("l", (L_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False))
, ("c", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("v", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("y", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("h", (L_, \l -> case l of [] -> True ; _ -> False))
, ("re", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("S", (L_, \l -> case l of [] -> True ; _ -> False))
, ("s", (L_, \l -> case l of [] -> True ; _ -> False))
, ("f", (L_, \l -> case l of [] -> True ; _ -> False))
, ("F", (L_, \l -> case l of [] -> True ; _ -> False))
, ("F*", (L_, \l -> case l of [] -> True ; _ -> False))
, ("B", (L_, \l -> case l of [] -> True ; _ -> False))
, ("B*", (L_, \l -> case l of [] -> True ; _ -> False))
, ("b", (L_, \l -> case l of [] -> True ; _ -> False))
, ("b*", (L_, \l -> case l of [] -> True ; _ -> False))
, ("n", (L_, \l -> case l of [] -> True ; _ -> False))
, ("W", (L_, \l -> case l of [] -> True ; _ -> False))
, ("W*", (L_, \l -> case l of [] -> True ; _ -> False))
instance Show ColorOperator where
instance Show TextOperator where
show Td = "Td"
show TD = "TD"
show Tm = "Tm"
show Tstar = "T*"
show TJ = "TJ"
show Tj = "Tj"
show Quote = "'"
show DQuote = "\""
show Tc = "Tc"
show Tw = "Tw"
show Tz = "Tz"
show TL = "TL"
show Tf = "Tf"
show Tr = "Tr"
show Ts = "Ts"
-}
stateOperator :: OperatorTable StateOperator
stateOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(C_m, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (W_, \l -> case l of [Raw _] -> True ; _ -> False)
, (J, \l -> case l of [Raw _] -> True ; _ -> False)
, (J_, \l -> case l of [Raw _] -> True ; _ -> False)
, (M, \l -> case l of [Raw _] -> True ; _ -> False)
, (D_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (R_i, \l -> case l of [Raw _] -> True ; _ -> False)
, (I_, \l -> case l of [Raw _] -> True ; _ -> False)
, (G_s, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False)
]
pathOperator :: OperatorTable PathOperator
pathOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(M_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (L_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (C_, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (V_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (Y_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (H_, \l -> case l of [] -> True ; _ -> False)
, (R_e, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (S, \l -> case l of [] -> True ; _ -> False)
, (S_, \l -> case l of [] -> True ; _ -> False)
, (F_, \l -> case l of [] -> True ; _ -> False)
, (F, \l -> case l of [] -> True ; _ -> False)
, (Fstar, \l -> case l of [] -> True ; _ -> False)
, (B, \l -> case l of [] -> True ; _ -> False)
, (Bstar, \l -> case l of [] -> True ; _ -> False)
, (B_, \l -> case l of [] -> True ; _ -> False)
, (B_star, \l -> case l of [] -> True ; _ -> False)
, (N_, \l -> case l of [] -> True ; _ -> False)
, (W, \l -> case l of [] -> True ; _ -> False)
, (Wstar, \l -> case l of [] -> True ; _ -> False)
]
colorOperator :: OperatorTable ColorOperator
colorOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(CS, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False)
, (C_s, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False)
, (SC, \_ -> True)
, (SCN, \_ -> True)
, (S_c, \_ -> True)
, (S_cn, \_ -> True)
, (G, \l -> case l of [Raw _] -> True ; _ -> False)
, (G_, \l -> case l of [Raw _] -> True ; _ -> False)
, (RG, \l -> case l of [Raw _, Raw _, Raw _] -> True ; _ -> False)
, (R_g, \l -> case l of [Raw _, Raw _, Raw _] -> True ; _ -> False)
, (K, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (K_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
]
{-
stateOperator (Cm, [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _]) = True
stateOperator (W, [Raw _]) = True
stateOperator (J, [Raw _]) = True
stateOperator (J_, [Raw _]) = True
stateOperator (M, [Raw _]) = True
stateOperator (D, [Raw _, Raw _]) = True
stateOperator (Ri, [Raw _]) = True
stateOperator (I, [Raw _]) = True
stateOperator (Gs, [Typed (NameObject _)]) = True
stateOperator _ = False
-}
textOperator :: OperatorTable TextOperator
textOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(Td, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (TD, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (Tm, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (Tstar, \l -> case l of [] -> True ; _ -> False)
, (TJ, \l -> case l of [Typed (Array _)] -> True ; _ -> False)
, (Tj, \l -> case l of [Typed (StringObject _)] -> True ; _ -> False)
, (Quote, \l -> case l of [Typed (StringObject _)] -> True ; _ -> False)
, (DQuote, \l -> case l of [Typed (StringObject _)] -> True ; _ -> False)
, (Tc, \l -> case l of [Raw _] -> True ; _ -> False)
, (Tw, \l -> case l of [Raw _] -> True ; _ -> False)
, (Tz, \l -> case l of [Raw _] -> True ; _ -> False)
, (TL, \l -> case l of [Raw _] -> True ; _ -> False)
, (Tf, \l -> case l of [Typed (NameObject _), Raw _] -> True ; _ -> False)
, (Tr, \l -> case l of [Raw _] -> True ; _ -> False)
, (Ts, \l -> case l of [Raw _] -> True ; _ -> False)
]
{-
textOperator (Td, [Raw _, Raw _]) = True
textOperator (TD, [Raw _, Raw _]) = True
textOperator (Tm, [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _]) = True
textOperator (Tstar, []) = True
textOperator (TJ, [Typed (Array _)]) = True
textOperator (Tj, [Typed (StringObject _)]) = True
textOperator (Quote, [Typed (StringObject _)]) = True
textOperator (DQuote, [Typed (StringObject _)]) = True
textOperator (Tc, [Raw _]) = True
textOperator (Tw, [Raw _]) = True
textOperator (Tz, [Raw _]) = True
textOperator (TL, [Raw _]) = True
textOperator (Tf, [Typed (NameObject _), Raw _]) = True
textOperator (Tr, [Raw _]) = True
textOperator (Ts, [Raw _]) = True
textOperator _ = False
-}
type ArgumentStackParser m = (MonadState [Argument] m, MonadParser m)
--type Operator a = (Bounded a, Enum a, Show a)
type OperatorTable a = Map ByteString (TypeChecker a)
type TypeChecker a = (a, [Argument] -> Bool)
parseShowable :: (Show a, MonadParser m) => a -> m a
parseShowable textOp = string (pack $ show textOp) *> return textOp
callChunk :: MonadParser m => OperatorTable a -> m (Either (TypeChecker a) Argument)
callChunk table =
(Right <$> choice [stringArg, nameArg, arrayArg])
<|> operatorOrRawArg
<?> "call chunk"
where
operatorOrRawArg = do
chunk <- takeAll1 regular <* blank
case table !? chunk of
Nothing -> return . Right $ Raw chunk
Just typeChecker -> return $ Left typeChecker
stackParser :: (ArgumentStackParser m, Operator a) => OperatorTable a -> m (Call a)
stackParser table = either popCall push =<< (callChunk table)
where
push arg = modify (arg:) >> stackParser table
popCall (operator, predicate) = do
arguments <- reverse <$> get
let call = (operator, arguments)
if predicate arguments then return call else fail (unpack $ code operator)
a :: (Operator a, MonadParser m) => OperatorTable a -> m (Call a)
a table = evalStateT (stackParser table) []
argument :: MonadParser m => m Argument
argument = Raw <$> takeAll1 regular <* blank
arrayArg :: MonadParser m => m Argument
arrayArg = Typed . Array <$> array <* blank
nameArg :: MonadParser m => m Argument
nameArg = Typed . NameObject <$> name <* blank
stringArg :: MonadParser m => m Argument
stringArg = Typed . StringObject <$> stringObject <* blank
type ParserWithFont = ReaderT FontSet (Parser Font)
pageContents :: FontSet -> ByteString -> Either String [Text]
pageContents fontSet input =
evalParser (runReaderT (page) fontSet) emptyFont input
several :: MonadParser m => m [a] -> m [a]
several p = concat <$> (p `sepBy` blank)
page :: ParserWithFont [Text]
page = several (graphicState <|> text) <* blank <* endOfInput <?> "Text page contents"
graphicState :: ParserWithFont [Text]
graphicState =
string "q" *> blank *> insideQ <* blank <* string "Q" <?> "Graphic state"
where
insideQ = several (command <|> graphicState <|> text)
ignore x = a x *> return []
command =
ignore stateOperator <|> ignore pathOperator <|> ignore colorOperator
text :: ParserWithFont [Text]
text =
string "BT" *> blank *> commands <* blank <* string "ET" <?> "Text operators"
where
commands = several (a textOperator >>= runOperator)
runOperator :: Call TextOperator -> ParserWithFont [Text]
runOperator (Tf, [Typed (NameObject fontName), _]) =
asks (! fontName) >>= put >> return []
runOperator (Tstar, []) = return ["\n"]
runOperator (TJ, [Typed (Array arrayObject)]) =
replicate 1 <$> foldM appendText "" arrayObject
where
appendText bs (StringObject outputString) =
mappend bs <$> decodeString outputString
appendText bs _ = return bs
runOperator (Tj, [Typed (StringObject outputString)]) =
replicate 1 <$> decodeString outputString
runOperator (Quote, [Typed (StringObject outputString)]) =
(\bs -> ["\n", bs]) <$> decodeString outputString
runOperator (DQuote, [Typed (StringObject outputString)]) =
(\bs -> ["\n", bs]) <$> decodeString outputString
runOperator _ = return []
decodeString :: (MonadFail m, MonadState Font m) => StringObject -> m Text
decodeString input = do
font <- get
either fail return . font $ toByteString input